The present invention relates to arrays of circuitry fabricated on substrates.
Sheng, K. C., Qiu, H., Sondeno, J. R., Lam, J. K., and Addiego, G., "Laser repair processes for mass production of LCD panels," Solid State Technology, June 1993, pp. 91, 92, 94, and 95, describe repair techniques for liquid crystal display (LCD) panels. As shown and described in relation to FIG. 4, open lines can be repaired using spare address lines and laser welds. A spare address line can be laser welded to an open line and thereafter addressed by the driver. FIG. 5 shows how laser welding can be performed with sufficient energy that two layers of metal connect across an insulator layer so that an open defect is bypassed by a new conductive path.
Lee et al., EP-A 546 780, describe a controller integrated circuit (IC) for active matrix liquid crystal displays with serial to parallel conversion of refresh data stream to support vertically split panels as well as multiple scan drives. Beginning at page 2 line 56, Lee et al. describe a common technique of splitting a high-resolution passive super-twisted nematic (STN) liquid crystal display (LCD) panel into top and bottom halves. Data lines are separated in the mid-panel and driven from both sides with different column drivers, effectively doubling the input bandwidth without requiring high speed driver ICs, but at the cost of preparing a dual-scan data stream.
Lee et al. indicate, however, that the technique has a serious drawback as panel resolution increases--splitting the data (column) line in the middle of the panel makes data lines accessible from only one side. This leads to reduced ability to test and repair the panel, especially for defects caused by breaks in split lines. If both ends of a line are accessible, the same defect may be tolerated by shorting the broken line outside the panel or providing drivers on both ends. To meet the input sampling requirements and to be more defect-tolerant, it would be more appropriate to split the panel vertically into left and right halves, rather than splitting it into top and bottom halves. Lee et al. describe techniques for splitting the panel vertically in relation to FIG. 7.